Methylhydrogenpolysiloxane composition for treating textile



United tates Patent i ME'IHYLHYDROGENPOLYSILQXANE COMPOSI- Tlio f Qa TREAHNG TEXTlL Heinz Eder, Munich, Germany, assignor to Wacker Qhernie G. :11. b. IL, Munich, Bavaria, Germany No Drawing. Application June 24, W53,

- 'S erialNo; 363,943

priority, application Germany July 9, 1952 2 Claims. c1. 2 222 This invention relates to a method of rendering textiles water repellent, in which method both an organes on compound and certain zirconium compounds are ar an "The treatment of textiles with various organosilicon compounds and organosiloxane polymers to render them water repellent is wellv known. Textiles so treated become outstandingly Water repellent, and the treatment will last quite well through several washings or dry cleanings. In order to obtain 'the fullest benefits of a treatment with organosilicon compounds, it is necessary to subject the treated material to heat, which brings about" the condensation of the organopolysiloxane which has been deposited or'formed on the textile fibers and 'thus'firmly binds the organosilicon compound to the fibers. i

Even though treatment with organosilicon compounds has great advantages over previously employed treatments with purely organic resins, waxes, etc., the general treatment of textiles with organosilicon compounds still has certain disadvantages. In order to obtain adequate condensation of the organosilicon compound and good adhesion thereof to the fibers, it is necessary tou'se' a comparatively high curing temperatu're; or, at lower temperatures, a rather longheating period. This heat treatment sometimes approaches very near to the decomposition or damaging temperature of the textile being treated. In the case of some textiles, e. g.,"cotton, the water repellent action of the organosilicon compounds is not completely satisfactory. Furthermore the retention of the water repellent properties of a silicone treated textile after washing with soap, soda, or detergents, or after dry' cleaning, is still subject to improvement.

It is an object of the present invention to provide improved water repellency and improved resistance to Washing and dry cleaning of textiles which are treated with organosilicon compounds.

In accordance with the present invention, it has been found 'that textile materials can be impregnated or treated with organosilicon compounds and cured at lower temperatures to give essentially better and longer lasting water repellency efiects if the textile is also treated with an aqueous solution of a zirconium compound which is capable of being firmly bound by, or fixed on the fibers. The treatment with the zirconium compound may take place either before, simultaneously with, or after the treatment with the organosilicon compound, for improved results are obtained no matter what the order of treatment with the two compounds ice maybe. The methodof this invention is conventional in all other respects. In other words, the major constituents employed inttheldefinedprocess can be applied by any of thefusual. dipping, spraying, brushing, or ,padding techniques ,alongiwiththe use of conventional washingtechniqueS. andcuring techniques in any suita le heated pna i ms- Anurnber of. organosilicon compounds are advocated in the art'as, being suitable for treating fabrics to render them water repellent. Such compounds include hydroyzeb e monom r c. ga esilane u h as the various alkoxy silanes, amino silanes, and halosilanes having variant o an c. radic l a. a y y y and allgaryl radicals attached to the silicon atom. Treatment with such materials depends upon either atmospheric moisture residual, moisture on the fibers, and/ or additional. water supplied. during the treatment to bring about the, condensation; or, polymerization of the hydrolyzable silaneson'the fabric oi =te x til e,sov treated. Partial hydrolyz a tes ot the above described silanes, i. e., materials contz i ining. bothSiOfii linkages and some unreacted, hydrolyzable substituents, have. also been em ployed. Numerous oilycor resinous organosiloxanes, as well as;,polyrne L containingpther types of, silioontosil-i con linkages, .e SiQHzSL S7Z+Si,-' and. SiCel-lrSi types of polymers, are also, employed.

Th 'rnostwidely known and commercially:important organosiliconfmaterialsafor, textile treatment are the methylliydrogensiloxane polymers or copolymers. These materials; are prepared. by the hydrolysis. of compound l0 the formula Cl-laHSiXg where X is a hydroyfza e radi lsuea s. r orineor e e ydr lyzable' methylhydli lgensilane can. be, cohydrolyzed with other hydroly zjable, organosilanesfe. g., CHaS-iCls, (CH'a)2SiCl2, (CHa)3SiCl, etc. to produceQsuitable;co= polymers, Another commercially important organosilicon textiletreatment employs amixtureof a meth: ylh dr en i d aep lym o p lym w a liquid m thrmdy em e P m or p ymer.

All of the above, described organosilicon. compounds are well known in theart of textile treating and do not need any detailed description, Th method of the present invention brings ,abouta degree of improvement in the treatment of textiles with any of the above describedorganosilicon compounds, and is applieable to, all such compounds.

The zirconium compounds employed are those which are soluble in water and which can befixed on the textile fibers. The'zi'rconyl (or z-irconoxy) salts of organic and inorganic acids are particularly preferred. Best results have been obtained ,by the use of'zirconium compounds such as Zirconyl chloride, zirconyl acetate, and zirconyl nitrate. Zirconyl sulfate and zircony-l carbonate are further examples v of suitable compounds. The so-called basic zirconyl salts such as ZrzO sClz are also suitable. the reaction of ZrOClz with NazCOs, Zirconyl ammonium carbonate [ZrOCO3(NH4)2CO3] is another example of a suitable commercially available Zirconium compound.

As' stated above the zirconium compound can be added either before or after treatment with the organosilicon compound. Both for convenience and for best results, however, it is preferable that thezircom'um co1 n- The latter compound can be prepared by pound and the organosilicon compound be used simultaneously. Naturally this can only be done when a polymeric rather than a hydrolyzable organosilicon compound is being employed. In treating textiles simultaneously with an organosilicon compound and a zirconium compound, an aqueous solution of the zirconium compound is added to an aqueous emulsion of the organosilicon compound to form the emulsion which is to be employed in treating the textile material. A preferred example of such a treatment is the use of an emulsion of a methylhydrogenpolysiloxane (as a polymet or copolymer, or mixture of such with other methylsiloxanes) to which one or more of the defined zirconium compounds has been added.

Suitable emulsifying agents for such organosilicon compounds have been described in the art. such emulsifying agents are those which are decomposed by heat, exemplified by the quaternary ammonium halides such as benzyl trimethylammonium chloride. It is beneficial to add small amounts of acetic acid to such an emulsion of a methylhydrogenpolysiloxane in order to prevent any undue evolution of hydrogen during storage.

It is also desirable to add a buffer, such as sodium acetate, to the final emulsion. The usual silicone condensation accelerators (or curing catalysts) can, of course, also be employed in the process in order to decrease the temperature and/or length of time that a treated material needs to be heated. Examples of such catalysts are the heavy metal salts of organic acids, such as lead and Zinc octoates and naphthenates.

After the textile material has been impregnated with an emulsion such as that described above, the material is dried and then preferably heated. Such a heat step is not absolutely necessary to the development of water repellent properties, but does tend to improve the properties of the product as well as to shorten the length of time required to attain such water repellent properties.

The zirconium salt content of the solution which is applied to the textile material can vary within wide limits, depending upon the material being treated and the type of properties desired. When the zirconium salt is employed in conjunction with an organosiloxane emulsion, it is preferable that the salt be present to the extent of from 0.2 to 2 percent by weight based upon the weight of the emulsion.

The term textile material" as employed herein is meant to refer to the raw fibers and yarns, as well as to the finished fabrics which have been knitted, woven, etc. from such yarns and fibers. The treatment is applicable to both natural and synthetic textile materials, e. g., wool, cotton, linen, rayon, nylon, artificial silk such as viscose, cuprammonium rayon, etc.

The treatment of textile materials according to this invention results not only in lowering of the condensation temperature of the silicones employed or decrease in the curing time, but also results in an improvement of the water repellent properties of the treated material as well as an increased resistance of the treated material toward washing and dry cleaning.

The following examples are illustrative only. All parts given are parts by weight.

Example 1 parts of zirconyl chloride were dissolved in 890 parts of hot water (about 80 to 90 C.) and the solution cooled. A solution of 9 parts of sodium acetate and three parts of glacial acetic acid in 88 parts of water was added thereto. Samples of cotton were dipped in this aqueous solution and then run through squeeze rollers. After drying, the samples were dipped in a 2 percent solution of a methylhydrogenpolysiloxane in methylene chloride. The treated material was then heated for from 4 to 10 minutes at 130-140 C. The material so treated had outstanding water repellent char- Preferably acteristics. The water repellent efiect was retained even after repeated washing and dry cleaning. When the experiment was carried out under identical conditions but without the zirconium salt, a complete cure of the treated material required at least twice as much time or, for the same heating period, a correspondingly higher temperature. The material treated without Zirconium addition resisted, at best, 5 to 6 standard washings (washing in 40 C. water which contains 0.3 percent soda and 0.5 percent soap) while the material which had been additionally treated with the zirconium salt could be washed in the same manner up to about 10 times without materially decreasing the water repellency.

Example 2 33.3 parts of a solution of 60 percent methylhydrogenpolysiloxane in methylene chloride was emulsified with parts of water, using an emulsifying agent such as benzyl trimethyl ammonium chloride and a high speed mixer, to give an emulsion containing 20 percent by weight of the silicone. This emulsion was diluted with 900 parts of a room temperature solution which was prepared by dissolving 10 parts of zirconyl chloride in 790 parts of hot water, cooling and adding thereto a solution of 9 parts sodium acetate and 3 parts glacial acetic acid in 88 parts water. Woolen samples were dipped in this emulsion, squeezed, dried, and cured for 5 to 10 minutes at l30l40 C. The treated material showed the same improved water repellency as that demonstrated in Example 1.

Example 3 33.3 parts of the emulsion of methylhydrogenpolysiloxane described in Example 2 was diluted with 900 parts of a room temperature solution which had been prepared by dissolving 13 parts of zirconyl nitrate in 790 parts of hot water, cooling, and adding a solution of 9 parts sodium acetate and 3 parts glacial acetic acid in 88 parts water. Textiles of polyamide fibers were dipped in this diluted emulsion, squeezed dry, and cured for 5 to 10 minutes at 130-140 C. The textiles so treated were more resistant toward washing and dry cleaning than the same material treated in the same manner but without the addition of the zirconium compound.

Example 4 The methylhydrogenpolysiloxane emulsion described in Examples 2 and 3 was diluted with a solution of 12.7 parts of zirconyl acetate in 900 parts of water and 3 parts parts of glacial acetic acid. A cellulose acetate fabric was impregnated with this emulsion and then dried and cured at C. for 10 minutes. This fabric exhibited the same improved water repellent properties and resistance to washing shown by the fabrics of Example 1.

In Example 2 there were used 10 parts of the zirconyl compound with 20 parts of the methylhydrogenpolysiloxane. This represents a ratio of 0.5 part of zirconyl compound per part of the siloxane and it is the basis for the lower extreme of the most preferred concentration. In Example 3 the ratio is about 13 parts of the zirconyl compound to 6.66 parts of the siloxane, which is a ratio of 1.95/1. Thus the higher extreme of the preferred range of concentration is about 2 parts of zirconyl compound per part of siloxane. Stated otherwise, it is preferred that the zirconyl salt be used in a concentration of from about 50 percent to about 200 percent by weight of the concentration of the methylhydrogenpolysiloxane.

That which is claimed is:

1. A composition suitable for treating textiles which comprises an aqueous emulsion of a liquid methylhydrogenpolysiloxane and a water soluble zirconyl salt, said salt being present in amount up to 2 parts by weight per part of methylhydrogensiloxane and said salt being present in amount of at least .2% by weight based on the total weight of the emulsion.

2. A composition suitable for treating textiles comprising an aqueous emulsion of a liquid methylhydrogenpolysiloxane and a zircOnyl salt selected from the group consisting of zirconyl chloride, zirconyl acetate and zirconyl nitrate, said salt being presentin amount up to 2 parts by weight per part of the methylhydrogensiloxane and in amount of at least .2% by weight based on the total weight of the emulsion.

References Cited in the file of this patent UNITED STATES PATENTS Norton Oct. 9, 1945 Wright Nov. 9, 1948 Van Mater Sept. 27, 1949 Warrick Jan. 17, 1950 Dennett Mar. 11, 1952 Dennett Mar. 11, 1952 Brown et a1 May 20, 1952 McNutly et a1 Aug. 24, 1954 

1. A COMPOSITION SUITABLE FOR TREATING TEXTILES WHICH COMPRISES AN AQUEOUS EMULSION OF A LIQUID METHYLHYDROGENPOLYSILOXANE AND A WATER SOLUBLE ZIRCONYL SALT, SAID SALT BEING PRESENT IN AMOUNT UP TO 2 PARTS BY WEIGHT PER PART OF METHYLHYDROGENSILOXANE AND SAID SALT BEING PRESENT IN AMOUNT OF AT LEAST 2% BY WEIGHT BASED ON THE TOTAL WEIGHT OF THE EMULSION. 